Device for introducing electric components into continuous tapes

ABSTRACT

The invention relates to a novel device for introducing (packaging) electric components that are punched out of a lead-frame into/in recesses or pockets of at least one tape that are made available at an insertion position. The insertion process is carried out using at least one component holder that can be displaced between a removal position and the insertion position.

[0001] The invention pertains to a device according to preamble, patent claim 1.

[0002] Devices or machines are known in the art that are also designated as so-called back-end machines and serve to stamp out electric components from a lead frame and, after various additional steps, for example measuring, laser labeling, etc., to insert them at a belt station in holders or cups of belts waiting there.

[0003] In these known back-end machines, the holders designed as vacuum holders are located on a transport element forming a closed loop, which is pulse driven in one direction of rotation, so that these holders with the components held there move over a relatively long distance from a pick up position, at which the components are stamped out of the lead frame, to a delivery or insertion position, at which the components are each then inserted in a holder of a belt.

[0004] Also known in the art are special lead frame designs in which the components in the lead frame are held not only by lead frame elements that form the connections after stamping of the components, but also by means of so-called “suspension noses”, which only engage with recesses of the housings of the components so that the components are still held in the lead frame after being stamped out, but can be removed easily, e.g. by pressing them out.

[0005] The object of the invention is to present a device having a simple and reliable design while enabling high performance in the insertion of components in belts. In order to achieve this object, a device as claimed in claim 1 is embodied.

[0006] In the device according to the invention, the insertion of components in belts directly from the lead frame, for which purpose the at least one holder, which for example is a vacuum holder, performs only a relatively short, back-and-forth stroke movement in the “first” axis direction, between a position above a component in the lead frame (pick up position) and a position (delivery or insertion position) above a waiting receptacle (cup) of the at least one belt. For removal or pick up of the respective component from the lead frame and for insertion of this component into the receptacle of the belt, another relative movement between the lead frame or belt and the at least one holder takes place in the “second” axis direction, i.e. preferably a movement of the at least one holder in this second axis direction.

[0007] Upon pick up, the components are already stamped out and are held in the lead frame only by suspension elements, which are formed for example from the suspension noses or from break-off positions, for example from the material of the component housing. A preferred embodiment of the invention provides for several components, with which during one cycle several components, preferably several components of different rows of the lead frame, can be removed from the latter and inserted into receptacles of one or more belts.

[0008] Further embodiments of the invention are the subject of the dependant claims.

[0009] The invention is described below in more detail based on a sample embodiment depicted in the following drawings:

[0010]FIG. 1 shows a simplified schematic representation of a device for insertion of electric components from a lead frame directly into a belt;

[0011]FIG. 2 shows the device of FIG. 1 in side view;

[0012]FIG. 3 shows a schematic cross section view corresponding to line I-I of FIG. 1;

[0013]FIG. 4 and 5 show an enlarged representation of details of FIGS. 1 and 2;

[0014]FIG. 6 shows a simplified representation of a stamped component in the lead frame.

[0015] In the drawings, 1 designates a lead frame and 2 designates electric components in the form of SMDs, for example transistors, which are located in several longitudinal and transverse rows in the lead frame 1. The electric components 2 are removed by means of the device or belt station generally designated 3 in the drawings from the lead frame 1 and inserted at a delivery or insertion position 5 in cups 6 of a belt 7 waiting to the side of the lead frame 1. The components therefore form longitudinal rows extending lengthwise to the belt, in the depicted embodiment a total of four longitudinal rows, and transverse rows extending crosswise to the belt, whereby in the depicted embodiment each transverse row has four components 2.

[0016] Preceding the belt station, in a work station of a total backend line machine not further depicted, the components 2 are already stamped from the lead frame 1 so far that connections 2′ of the components 2 no longer connected with the remaining lead frame are formed from original elements of the lead frame and which (connections) extend away from the body 2″ of the components. The components 2 are still held only by so-called suspension noses 8 of the lead frame 1 that engage with recesses of the housing 2″, as represented schematically in FIG. 6. The components 2, the connections 2′ of which were already bent in the required manner at a preceding bending station not depicted or upon stamping, and the electric values of which were checked or measured in a preceding measuring station likewise not depicted, can be removed from the lead frame very easily by pressing them out.

[0017] A special feature of the belt station 3 consists in the fact that in each cycle one component 2 is removed from each longitudinal row of the lead frame 1 and each component is inserted into a respective cup 6 of a belt 7.

[0018] For this purpose, there are four belts 7 waiting at the insertion position 5 in the depicted embodiment corresponding to the number of the longitudinal rows of the components 2 in the lead frame 1, which (belts) are arranged there with their longitudinal extension horizontally and perpendicularly to the longitudinal extension of the lead frame 1, in a common center or axis distance, which corresponds to an even-numbered multiple of the distance between the transverse rows of components in the lead frame 1. In the depicted embodiment, the axis distance of the belts 7 is equal to two times the distance of the transverse rows in the lead frame 1.

[0019] As indicated in FIG. 1 by the line A-A, the components 2 are removed diagonally from the lead frame 1 in each cycle, while the components 2 are inserted into the waiting cups 6 corresponding to the line B-B of FIG. 1 parallel to the longitudinal extension of the lead frame 1. In each cycle, the lead frame is advanced in preparation for the next cycle by one stroke equal to the distance of two transverse rows corresponding to the arrow C, whereby this advance can already be initiated when the components 2 are removed from the lead frame 1.

[0020] After insertion of the components 2 into the cups 6 waiting at the delivery position 5, the belts 7 are further moved by means of a suitable drive not depicted, by one stroke that is equal to the distance between two cups 6 on the belts 7. If no component 2 was inserted into a waiting cup 7 in a cycle because this component was lost during the transfer from the pick up position 4 to the delivery position 5 or was intentionally removed from the lead frame 1 as a faulty component for example in a preceding measuring station, a repair program is activated, i.e. no advance of the affected belt takes place after the cycle, so that cups 6 of this belt not filled during this cycle are available for insertion of a component 2 in the following cycle, thus preventing component gaps in the belt 7.

[0021] In particular, the belt station 3 consists of several pushers 9, which can be moved (double arrow E) separately on a common guide and stroke element 10 in a first axis direction perpendicular to the longitudinal extension of the lead frame 1 and parallel to the surface of this lead frame, i.e. in horizontal direction perpendicular to the longitudinal extension of the lead frame 1. On the free end of each pusher 9 there is a pick-up element or holder for receiving and holding the component 2, in the depicted embodiment in the form of a vacuum pipette 11. Each pusher 9 is guided in the guide elements 10 in such a way that its vacuum pipette 11 can be moved between a first position at the pick up position 4 and over a longitudinal row of the components 2 in the lead frame 1 and a second position at the insertion position 5 and over a cup 6 of a belt 7, whereby the vacuum pipettes 11 in the first position on the line A-A are located over another longitudinal row of the components 2 diagonally to the longitudinal extension of the lead frame 1 and in the second position on the line B-B parallel to the longitudinal extension of the lead frame 1. For this purpose, the vacuum pipettes and the pushers 9 execute strokes of different sizes in this horizontal movement, the upper vacuum pipette 1 and its pusher 9 in FIG. 1 executing the largest horizontal stroke and the lower vacuum pipette 11 and its pusher 9 executing the smallest stroke. Each pusher 9 and its vacuum pipette 11 is pre-tensioned by means of a separate spring 13 in the second position of the horizontal stroke. The vacuum pipettes 11 and their pushers 9 can be moved separately into the first position of their horizontal stroke by means of a drive 14.

[0022] The drive 14 consists, e.g., of a drum 15, which can rotate back and forth by means of a rotor, for example a servo motor, on an axis perpendicular to the movement of direction E of the pushers 9, by a pre-defined angle, as indicated in FIG. 2 by the double arrow F. In the depicted embodiment the axis of the drum 15 is a horizontal axis that is parallel to the longitudinal extension of the lead frame 1.

[0023] The drum 15 has regular cylindrical drum sections 15 a-15 d each with a different diameter, each of which is allocated to a pusher 9 and the drum section 15 a having the largest diameter for the upper pusher 9 in FIG. 1 with the largest horizontal stroke and the drum section 15 d having the smallest diameter for the lower pusher 9 in FIG. 1 with the smallest horizontal stroke. One end of a pulling element 16 is guided across each drum section 15 a-15 d, for example a pull cable, which engages with its other end the allocated pusher 9 on the end opposite the vacuum pipette 11 in the respective drum section 15 a-15 d. The pulling elements 16 are each guided across a deflection pulley 17, so that the drum 15 can be located below the plane of the movement of the pushers 9 and in particular the sections 16′ of the pulling elements 16 extending between the end of the respective pusher 9 and the deflection pulley 17 are in a common horizontal plane, in which the axes of the pushers 9 are also located.

[0024] The diameters of the drum sections 15 a-15 d are coordinated so that in a specified swing angle F of the drum 15 the pushers 9 execute the required different movements or strokes. It is basically also possible to limit these different strokes of the pushers 9 by means of suitable stops.

[0025] The drive for the drum 15 is preferably designed so that a soft start takes place at the beginning of each stroke from the pick up position 4 into the delivery position 5 and a soft stop takes place at the end of this stroke, so as to prevent accelerations and decelerations, which can cause the components 2 suspended on the vacuum pipettes 11 to be lost.

[0026] Each vacuum pipette 11 consists in the manner known in the art of one pipette body 11′ tapered at its lower end, with an open hole 11″ on the bottom of the pipette body, which (hole) can be connected in an individually controlled manner by means of a vacuum connection, e.g. by means of a connection 9′ extending partially also in the respective pushers 9 and by means of a control valve of a control valve device 27 with a vacuum or negative pressure source 28. The distance of the vacuum pipettes 11 in the longitudinal direction of the lead frame 1 is equal to the axis distance of the belts 7. The axis of the hole 11″ of each vacuum pipette 11 is in a common vertical plane with the middle axis of a belt 7. The distance of the belts 7, which is a multiple, i.e. two times the distance of the transverse rows of the components 2 in the lead frame 1, provides sufficient space for the vacuum pipettes 11 despite the very close arrangement of the components 2 in the lead frame 1.

[0027] In the depicted embodiment, the individual vacuum pipettes 11 can swivel or rotate on bearings in the corresponding pusher 9 on their vertical axis. Each pusher 9 is provided for this purpose with a swivel drive 19 for each vacuum pipette 11, with which this pipette 11 can rotate in a controlled manner on a specified angle, for example 180° on its vertical pipette axis, in order to turn components 2, for example.

[0028] A rotation or swivel angle of less than 180°, for example 90°, is also conceivable for the vacuum pipettes 11, in order to insert the components 2 in the cups 6 of the belts 7 in an orientation with respect to the longitudinal axis of the belt corresponding to the orientation of the component 2 in the lead frame 1 with respect to the longitudinal axis of the lead frame.

[0029] The actuating device 19 for the controlled turning of the respective vacuum pipette 11 consists in the depicted embodiment of a servo component 20 in the form of a pneumatic cylinder, which works between a bearing on the pusher 9 and one end of a belt or strap 21, which is guided by a belt pulley 22 and the other end of which is connected with one end of a spring 23, the other end of which is held on the pusher 9. The belt pulley 22 is connected to drive the respective vacuum pipette 10 and is provided with radially extending pins 24 that engage in perforations of the belt 21, so as to enable defined control of the angular rotation of the respective vacuum pipette 11 on its vertical axis.

[0030] The guide and stroke element 10 is located together with the drum 15, the rotation or swivel drive for this drum and the deflection pulleys 17 on a machine element or slide 25, which can move vertically up and down by a specified stroke (double arrow G), for example by means of a common drive of the overall device, whereby the drive for the drums 15 is coordinated with this vertical stroke of the slide 25 and therefore of the guide element 10 and the pushers 9 in such a way that the horizontal stroke of the pushers 9 takes place only when the guide element 10 is raised. Below the horizontal plane of the lead frame 1 there are tappets 26, the parallel tappet axes of which are oriented vertically and which execute a tappet or stroke movement corresponding to arrow H, synchronously with the stroke of the guide element 10. The tappets 26 are distributed diagonally to the longitudinal extension of the lead frame 1 in such a way that each tappet 26 is arranged in the same axis with a vacuum pipette 11 located in the pick up position 4 or in the first position.

[0031] The principle of the belt station 3 can therefore be described in detail as follows: The vacuum pipettes 11 are in the pick up position 4 with the guide element 10 raised vertically. Below each vacuum pipette 11 there is a component 2 in the lead frame 1. By means of the slide 25 and the guide element 10 the pushers 9 and therefore the vacuum pipettes 11 are lowered so that each vacuum pipette 11 comes to bear with the end there of the hole 11″ against a component 2. By applying negative pressure to the vacuum pipettes 11 by means of control valves located in the vacuum connection, the respective component 2 is fixed with the top of its housing 2″ on the vacuum pipette 11. The tappets 26 bear against the bottom of the housing 2″ so that each component is held between a vacuum pipette 11 and a tappet 26. Afterwards, all vacuum pipettes 11 are moved vertically upward by lifting the slide 25.

[0032] The tappets 26 follow the movement of the vacuum pipettes 11 upward as long as the components 2 are being separated from the lead frame 1. The clamping of the components 2 between the vacuum pipettes 11 and the corresponding tappets 26 prevents twisting of the components 2 when they are pressed out of the lead frame or upon release of the suspension noses 8 from the components 2. The further lifting of the guide elements 10 causes the vacuum pipettes 11 to be raised vertically until the components 2 suspended on these pipettes 11 by means of the vacuum are at a sufficient distance from the top of the lead frame 1 and are also at a distance from the top end of the tappets 26. Afterwards, the drive of the drum 15 is actuated for the horizontal stroke, so that the vacuum pipettes 11 are moved into the insertion position 5, above a cup 6 waiting at this insertion position. This movement takes place by means of releasing the springs 13 and by unwinding the pulling elements 16 from their respective drum section 15 a-15 d.

[0033] As soon as the vacuum pipettes 11 have reached the insertion position 5, the slide 25 causes all pushers 9 and the vacuum pipettes 11 to be lowered, so that each component 2 suspended on a vacuum pipette is inserted into a cup 6. After insertion of the components, the vacuum at the vacuum pipettes 11 is cut off, so that they release the components 2 and are then removed from the respective cup 6 through renewed lifting of the slide 25. Driving the drum 15 in the opposite direction causes the vacuum pipettes 11 to be returned to the pick up position 4 in a subsequent return stroke.

[0034] The invention was described above based on a sample embodiment. It goes without saying that numerous modifications and variations are possible without abandoning the underlying inventive idea of the invention. In addition to the repair program described above, for example, it is also possible to insert the components 2 in only one of the belts 7 at the end of a batch, for example with the upper vacuum pipette 11 in FIG. 1, with which the components 2 are then removed from each transverse row of the lead frame 1 one after the other and inserted into the cups 6 of the upper belt 7 in FIG. 1. For this purpose, the drive for the drum 15 is designed so that the corresponding differing strokes for the vacuum pipette 11 are possible.

[0035] It was assumed above that the drive 14 has a common drum 15 for all pulling elements 16 and holders 11. However, separate drives 14 or drums 15 can also be provided for the individual holders 11 or for several groups of at least two holders each, in which case they would be able to be controlled separately.

Reference symbols

[0036]1 lead frame

[0037]2 component

[0038]2′ connection

[0039]2″ component body

[0040]3 belt station

[0041]4 pick up position

[0042]5 insertion position

[0043]6 cup

[0044]7 belt

[0045]8 suspension nose

[0046]9 pusher

[0047]9′ vacuum channel

[0048]10 guide element

[0049]11 vacuum pipette

[0050]11′ pipette body

[0051]11″ pipette hole

[0052]13 spring

[0053]14 actuator

[0054]15 drum

[0055]15 a-15 d drum sections

[0056]16 pulling element

[0057]16′ pulling element sections

[0058]17 deflection pulleys

[0059]18 stop

[0060]19 actuator unit

[0061]20 servo component

[0062]21 belt

[0063]22 belt pulley

[0064]23 spring

[0065]24 pin

[0066]25 slide

[0067]26 tappet

[0068]27 valve

[0069]28 negative pressure or vacuum source

[0070] A-A, B-B line

[0071] C lead frame feed device

[0072] D belt feeder

[0073] E horizontal stroke of vacuum pipette

[0074] F swing angle

[0075] G vertical stroke 

1. Device for insertion (belting) of electric components (2) stamped in a lead frame (1) into inserts or holders of at least one belt (7) on an insertion position (5) by means of at least one holder (11) movable between a pick up position (4) and the insertion position (5), characterized in that for insertion of the components directly from the lead frame (1), which has the stamped components (2) that are still held in the lead frame (1) by means of suspension elements (8) in at least two longitudinal rows extending in the direction of the lead frame, the at least one holder (11) can be moved between the pick up position (4) over one longitudinal row of components and the insertion position (5) in a first axis direction crosswise to the longitudinal extension of the lead frame (1).
 2. Device as claimed in claim 1, characterized in that the at least one holder (11) and be moved horizontally in the first axis direction (E), preferably over a plane that is formed by the lead frame (1) at the pick up position (4).
 3. Device as claimed in claim 1 or 2, characterized in that the insertion position (5) is located on a longitudinal side of the lead frame (1).
 4. Device as claimed in one of the foregoing claims, characterized in that the at least one belt (7) is located at the insertion position (5) with its longitudinal extension crosswise or perpendicular to the longitudinal extension of the lead frame (1).
 5. Device as claimed in one of the foregoing claims, characterized in that the at least one belt (7) is located at the insertion position (5) with its longitudinal extension parallel to the longitudinal extension of the lead frame (1)
 6. Device as claimed in one of the foregoing claims, characterized in that the at least one holder (11) can be moved in a second axis direction (G), which is crosswise or perpendicular to the first axis and to the plane that the lead frame (1) forms at the pick up position (4).
 7. Device as claimed in one of the foregoing claims, characterized in that the at least one holder (11) is located on a slide (9), which can slide in the first axis direction guided in a second slide (10), and that the second slide (10) can be raised and lowered in the second axis direction by a drive.
 8. Device as claimed in one of the foregoing claims, characterized in that several holders (11) are provided for that can be moved at least in the first axis direction (E), preferably for the simultaneous pick up of several components (2) from the lead frame (1) and for the simultaneous insertion of each of these components (2) into a respective receptacle (6) of the at least one belt (7).
 9. Device as claimed in claim 8, characterized in that the number of holders (11) is the same as the number of longitudinal rows of components (2) in the lead frame (1).
 10. Device as claimed in claim 8, characterized in that the number of holders (11) is an integral fraction of the number of the number of longitudinal rows of components in the lead frame (1).
 11. Device as claimed in claim 8, characterized in that the number of holders (11) is an integral multiple of the number of longitudinal rows of components in the lead frame (1).
 12. Device as claimed in one of the foregoing claims, characterized in that the number of belts (7) is the same as the number of holders (11).
 13. Device as claimed in one of the foregoing claims, characterized in that the at least one holder (11) can be moved in the first axis direction (E), controlled with a varying stroke.
 14. Device as claimed in one of the foregoing claims, characterized in that the individual holders (11) can be moved at least in the first axis direction (E), each with a different stroke, from the pick up position (4) into the insertion position (5).
 15. Device as claimed in one of the foregoing claims, characterized in that with several belts (7), the receptacles (6) of the belts (7) waiting at the insertion position (5) are arranged on a first common axis or line (B-B), which for example is parallel to the longitudinal extension of the lead frame (1) at the pick up position (4).
 16. Device as claimed in one of the foregoing claims, characterized in that the holders (11) in the pick up position (4) are arranged on a second common axis or line (B-B), which encloses an angle smaller than 90° with the longitudinal extension of the lead frame (1) at the pick up position (4).
 17. Device as claimed in one of the foregoing claims, characterized in that at least one tappet (26) provided for at the pick up position (4) can be moved perpendicularly to the plane of the lead frame (1) such that the respective component (2) to be removed from the lead frame (1) is suspended between the tappet (26) and the holder (11) during said pick up.
 18. Device as claimed in one of the foregoing claims, characterized in that the holders (11) are each located on a separate first slide (9).
 19. Device as claimed in one of the foregoing claims, characterized in that all first slides (9) are located on a common second slide (10).
 20. Device as claimed in one of the foregoing claims, characterized in that the movement of the at least one holder (11) or the slide (9) containing this holder is effected by means of a cable, preferably against the effect of a pull-back spring (13).
 21. Device as claimed in claim 20, characterized in that the cable has at least one drum (15) driven by at least one drive motor, for example a servo motor.
 22. Device as claimed in one of the foregoing claims, characterized in that with several holders (11), a separate drive is provided for each holder (11) or for each group of at least two holders (11) for the stroke in the first axis direction (E).
 23. Device as claimed in one of the foregoing claims, characterized in that with several holders (11), a common drive is provided for all holders (11) at least for the stroke in the first axis direction (E).
 24. Device as claimed in claim 23, characterized in that the common drive (14) is designed for a varying stroke of the holders (11).
 25. Device as claimed in one of the foregoing claims, characterized in that for the simultaneous movement of several holders (11) or the corresponding first slides (9) in the first axis direction, a separate cable (16) is provided for each holder (11) or for each slide.
 26. Device as claimed in one of the foregoing claims, characterized in that for all cables (16) there is a common drum (15) with drum sections (15 a-15 d) for each respective cable, and that the drum sections (15 a-15 d) preferably have a different drum diameter for different strokes in the first axis direction.
 27. Device as claimed in one of the foregoing claims, characterized in that the holders are vacuum holders or vacuum pipettes (11).
 28. Device as claimed in one of the foregoing claims, characterized by an actuating device (19) for rotating or swiveling the at least one holder (11) on an axis extending parallel to the second axis. 